The Economics of Multi-Network Access

Abstract

Traditionally, a cell phone remains on a single, primary mobile network operator (MNO) as long as it is available, and roams onto another MNO only when outside the primary MNO's coverage. Multi-network access (MNA) is a new scheme where a cell phone may use any one of multiple MNOs at any place, anytime. One such example is a multi-operator mobile virtual network operator (MO-MVNO) like Google Fi. This paper quantifies how much MNA can reduce the cost of cellular data services, and shows that the amount of infrastructure and/or spectrum resources needed to produce a given network capacity can be reduced by over 20%. Greater resource savings can be realized if MNA-capable devices attach to towers of higher SINR rather than higher expected data rate. The amount of resources saved increases faster than linearly with increasing fraction of MNA-capable devices on the network, so as an MO-MVNO gains market share, it could demand better wholesale prices from partner MNOs. If the distribution of traffic volume between partner MNOs shifts significantly with MNA, an MNO losing traffic share may not have an incentive to participate in MNA unless it could demand a much higher wholesale price than other partner MNOs, possibly close to or even above the retail price net of market cost. The eventual economic impacts on each operator adopting MNA are the result of complex considerations involving not only business decisions like investment and wholesale pricing, but also technical parameters like network selection algorithms and resource allocation schemes.